MEDIOLATERAL OR LATEROMEDIAL POSITION
Note: For possible trauma if site of interest is in area of proximal femur, a unilateral trauma hip routine is recommended. For nontrauma lateral of mid-and proximal femur.
Pathology Demonstrated:
- Mid and distal femur is demonstrated, including knee joint for detection and evaluation of fracture and/or bone lesions.
Technical Factors:
- IR size - 35 x 43 cm (14 x 17 inches), lengthwise
- Moving or stationary grid
- 75 +- 5 kV range
- Because of anode heel effect, place the hip of the patient at cathode end of x-ray beam.
- mAs: 7
Shielding:
- Place lead shield over pelvic area to shield gonads.
Patient Position:
- Take radiograph with patient in the lateral recumbent position, or supine for trauma patient.
Part Position:
Lateral Recumbent:
- Flex knee approximately 45 degree with patient on affected side, and align femur to midline of table or IR.
- Place unaffected leg behind affected leg to prevent overrotation.
- Adjust IR to include knee joint (lower IR margin should be approximately 2 inches [5 cm] below knee joint). A second IR to include the proximal femur and hip generally will be required on an adult.
Trauma Lateromedial Projection:
- Place support under affected leg and knee and support foot and ankle in true AP position.
- Place cassette on edge against medial aspect of thigh to include knee, with horizontal x-ray beam directed from lateral side.
Central Ray:
- CR perpendicular to femur and IR directed to midpoint of IR
- Minimum SID of 40 inches (100 cm)
Collimation:
- Collimate closely on both sides to femur with end collimation to IR borders.
Radiographic Criteria:
Structure Shown:
 |
| lateral distal femur |
- Distal two-thirds of distal femur, including the knee joint, is shown.
- Knee joint will not appear open, and distal margins of the femoral condyles will not be superimposed because of divergent x-ray beam.
Position:
- True lateral: Anterior and posterior margins of medial and lateral femoral condyles should be superimposed and aligned with open femoropatellar joint space.
Collimation and CR:
- Femur should be centered to collimation field with knee joint space a minimum of 1 inches (2.5 cm) from distal IR margins.
- Minimal collimation borders should be visible on proximal and distal margins of IR.
Exposure Criteria:
- Optimal exposure with correct use of anode heel effect will result in near uniform density of entire femur.
- No motion is present; fine trabecular markings should be clear and sharp throughout lenght of femur.
